Contacting apparatus



Dec. 6, 1949 F. MELVILL I 2,490,079

CONTACTING APPARATUS Filed April 18, 1944 5 Sheets-Sheet 1 ogggggg...

Q60 9 ofofozofofozofof INVENTOR Fen/v0; L. /1 W41.

BY @ww ATTORNEY Dec. 6, 1949 MELVlLL 2,490,079

CONTACTING APPARA'JIUS Filed April 18, 1944. 3 Sheets-Sheet 2 INVENTOR I .I- PEA/V675 1. N62 V/AL ATTORNEY Dec. 6, 1949 F. L. MELVILL 2,490,079

CONTACTING APPARATUS Filed April 18, 1944 3 Sheets-Sheet 3 INVENTOR fieAA/c/J 4. M54 I/ILL ATTORNEY Patented Dec. 6, 1949 U N I T ED STAT ES PATEN T :0 FF ICE .2,490,079 CONTACTING APPARATUS Francis L.'Melvill, New Y0rk,-N.Y.

Application AprillS, 1944,,Serial No.-.531,589

14 Claims. (01. 261-940 This invention relates to 'apparatus for the contacting of gases or vapors and liquids. Although the invention has a wide range of utility, it is particularly useful in connection with contacting methods and apparatus such as are-employed for the absorption, ccoling, -'drying,-cleansing or humidifying "of gases, for the evaporation, cooling or heating ofiliquids, or for reaction purposes. Such devices may, for example, take the form :of 'fractionating -towers,-scrubbers, cooling towers and the like. In such apparatus, a packing is usually employed for effecting .intimate contact between the descending liquid and theascending gas or vapor. As used -.herein and in the claims, the term fgas includes vapor within .its scope.

The invention provides a new andimproved countercurrent gas and .liquid contact packing by which theflowof liquid downwardly through a treatingchamber is efiectedina regular predetermined symmetrical manner to assure uniform distribution of the liquid throughout the liquid flow area of the chamber, to-offer maximumliquid surface to the-actionlof the ascending gas, to

retain the descending liquid for :a period long enough to assure effective interaction between the liquid and the gas,v and to allow free circulation of the ascending .gas.

The invention provides a .novel ,packing for gas and liquid contacting apparatus, which avoids the presence .of unequalgasor liquid passages, causing channelingor segregation of the flowing gas in open spaces and of the liquid along surface areas, whereby at anycross-section of thepacking at right angles to'the general direction of countercurrent'flow of the liquid and'the gas, the composition of the gas and-liquid is substantially uniform.

The invention also provides .a new and improved packing of thegeneralcharacter-described, which feeds'and spreads out theliquid-even'ly in a thin film and in regular predetermined-manner as it descends ina treating chambergsothat even dis tribution of the liquid-throughoutthe flowareao'f the chamber is affordedwhich provides-themaximum of efiective (i. e., wetted surface area per unit of packing space, which o'ifers minimum-of resistance to the passage of the ascending gas, and which affordsathe maximum toftintimacy of contact and inter-actionibetween liquid and gas,

so that equilibrium'between' thematerial'in: either phase immediatelyradjacent itogthe interfacegand the main bulk of :theumaterial comprising ;'the

phase is rapidlyattaine'd.

In operation .liquid iscxsubdividedrin :the .rpac-king of the present invention into a predetermined number of thin exposed streams which are directed along respective substantially uniform zig-zag coursessufiiciently close together and at such wave phase relationship as to merge the 'apices of adjoining stream courses at regular equally spacedzonea'whereby groups of adjoining streams merge and --are intermixed at these zones,and'are then subdivided into a corresponding number of'thinstreams forsubsequentsmergence withother streams. The mixing zonesare staggered so that a networkof thinliquidstreams merging in groupsat fixed intervals and following a predetermined pattern is .formed, thuslaffording-uniform distribution :of the liquid across the fullwidth of the fiowarea. 1The.,gas is circulated upwardly through the spaces .formcd betweenitheliquid streams and into intimate contact with the streams, so thatefiective interactionbetween the liquid-and the gasis assured.

Packing embodying the invention comprises slender packing elements in the form 'of rods, Wires, tubes, flat strips ;or the like, which are shapedandarranged-to form-a network .of predetermined pattern, and to define symmetrical -.courses;a1ong which the deed-liquid is-directed as thin exposed filmiform streams. These streams encircle the elements, so that comparatively large surface streamareas are exposed in relationship .to the cross-sectional areas of the streams. The packing elements extend .converglngly downwardly in groups toward junctures at predetermined equally spaced intervals, to form mixing ,zones where streams of one group merge and are intermixed, and extend divergingly downward from these juncture zones in groups of similar number to subdivide and redistribute the merged streamsinto a corresponding number of other streams. The liquid "flowing down a single element of the packing is regularly mixed'with liquid flowing down adjacent elements of the packing, and the resulting mixture is then redistributed 'amongelements diverging fromthemixingzone,

'eachof these redistributed streams carrying substantially the same aliquot part of =th'e liquid reaching :the mixing zone from :above.

The invention will be understood from the following description when considered in :connection with the accompanying drawings' formingaa r part thereof a and "in which:

Fig. 1 is a fragmentary axial vertical section, somewhat diagrammati 'of aggas and :liquidcontacting device containing raupacl ing embodying wthe invention;

Fig. v2 is a -transverse section, somewhat diagrammatic, of the contacting device taken on line 22 of Fig. 1;

Fig. 3 is a side elevation of a pair of generally horizontal zig-zag packing elements contiguously arranged. in the same plane to form a mesh strip, and constituting one embodiment of the invention;

Fig. 4 is a fragmentary side elevation of a form of packing the constituent elements of which are similar to those shown in Fig. 3, and are secured together against relative movement in accordance with one embodiment of the invention;

Fig. 5 is a section taken on line 5-5 of Fig. 4;

Fig. 6 is a fragmentary side elevation of another form of packing similar to that indicated in Figs. 4 and 5, except that the packing elements are secured together in a different way against relative movement in accordance with another embodiment of the invention;

Fig. 7 is a section taken on line 'i--! of Fig. 6;

Fig. 8 is a fragmentary side elevation of another form of packing similar to that shown in Figs. 4 and 5, except that the packing elements are diiferently secured together against relative movement in accordance with still another embodiment of the invention;

Fig. 9 is a section taken on line 99 of Fig. 8;

Fig. 10 is a fragmentary side elevation of another form of packing embodying the invention, the constituent zig-zag elements of the packing being shown extending generally vertically with contiguous elements in the same plane;

Fig. 11 is a fragmentary side elevation of another form of packing embodying the invention, similar to that shown in Fig. 10 excepting that the elements are interconnected against relative displacement in a different way;

Fig. 12 is a side elevation of a packing element similar to that indicated in Fig. 3, the two contiguous elements, however, being shown arranged generally horizontally in overlapping relationship to form a mesh strip embodying the invention;

Fig. 13 is a section taken on line |3-l3 of Fig. 12;

Fig. 14 is a fragmentary side elevation of another form of packing embodying the invention, the constituent mesh strips of the packing being similar to those shown in Figs. 12 and 13;

Fig. 15 is a section taken on line l5-I5 of Fig. 14;

Fig. 16 is a fragmentary side elevation of still another form of packing, in which contiguous elements are arranged generally horizontally in overlapping relationship, but are interconnected in another way in accordance with another embodiment of the invention;

Fig. 1'7 is a section taken on line l'll1 of Fig. 16;

Fig. 18 is a fragmentary side elevation of another form of packing embodying the invention, the zig-zag elements being generally horizontal and the different layers of the elements being regularly displaced out of wave phase to a difierent extent from that shown in the other illustrated form; and

Fig. 19 is a section taken on line [9-19 of Fig. 18.

Referring to Figs. 1 and 2 of the drawings, the liquid and gas contacting device shown, comprises a vertical cylindrical column or tower l0 containing packing II of the invention. The

gas to be contacted is delivered to the lower portion of the tower [0 below the packing II, and fiows upwardly through the packing, while the liquid is fed to the upper portion of the tower above the packing, and flows downwardly through the packing and in intimate contact with the ascending gas in a manner to be described. The liquid is desirably delivered to the upper portion of the tower in and over the packing II in such scattered form as to be spread substantially evenly over the top of a packing ll, so that the liquid is distributed substantially uniformly throughout the packing at its upper end. For that purpose, the liquid may be delivered over the packing H in spray form, or may be delivered by a liquid feed device similar to that shown and described in my copending application Serial No. 536,306, filed May 19, 194.4, to feed the liquid in predetermined equally spaced thin streams over the packing.

The packing H is shown occupying the central portion of the tower l0, while the diametrically opposite side chordal sections I2 of the tower are left vacant 0r unpacked. A pair of partition plates E3 on the chordal sides respectively of the packing ll, prevent fiow into or out of the packing through those sides. The unpacked spaces l2 of the tower is! may be sealed either at the bottom or the top in any manner well-known in the art, to prevent by-pass flow through these spaces. The clearance between the circular peripheral portions of the packing H and the corresponding wall of the tower I0 may be sealed by any suitable means, as for example by means of layers M of glass wool.

In the form of the invention shown in Fig. 3, the packing 1! comprises a series of slender elements 16 which may be in the form of wires, tubes, rods or fiat strips, and which are shown specifically as solid cylindrical rods. These packing elements !6 are identical in cross-sectional size, shape and finish, and their surfaces are of such material and finish as to be substantially wetted by the liquid under normal operating conditions. For that purpose, the packing elements are desirably of a material, such as metal or plastic for example, having the necessary finish to afford the required wetting properties.

Although the packing elements 16 are shown of cylindrical stock, as far as certain aspects of the invention are concerned, they may be of any suitable symmetrical cross-sectional shape. For example, the surface of the elements may be grooved, fluted or otherwise treated to form a regular pattern thereon. These surface grooves may extend parallel to the longitudinal axis of the elements it, 01' may extend helically in the form of a thread. Such surface grooving of the elements [6 may be provided to increase the liquid carrying capacity of the elements. Also, instead of using single rods, wires or the like, as far as certain aspects of the invention are concerned, each of the packing elements may consist of multiple wires braided or helically twisted together, or laid side by side.

Each of the packing elements IB is regularly zig-zagged to form a plurality of successive oblique turns or sections ll of equal lengths and including equal angles, which need not necessarily be right angles. These elements I6 are arranged in general horizontal directions and in vertical planes, so that adjoining sections I! of an ele- 'awcsm 5 ment extend obliquely at the *"same inclination with the vertical. Contiguousel'ements Hi are disposed in reversed or inverted superposed relationship with "the valley "'or troug'h apices 18 of "the upper element inregistering abutment with v the peak apices 19 respectively of the lowerelement. The two contiguous superposed elements 16 thereby define therebetween a-series of horizontally adjoining meshes 2|, which desirably are in the form of equilateral parallelograms, and which are specifically shown as squares. 'Where the opposed apices I3 and 1-9 "of "vertically adjoining elements It come togetherjthey'form liquid mixing junction zones 22. Since all the elements I6 are substantially identical, except *perhaps in overall lengths, any two adjoining'oblique sections H of an upper element converging'downwardly towards a mixing zone 22, "will have the same inclinations with respect to'the vertical, and

the'two'correspondin'g sections H ofalowerele- 'ment contiguous with the upper element will diverge obliquely downwardly from the zone 22 at an inclination substantially'e'qual to that of the upper sections.

The liquid flows downwardly along the oblique converging sections ll of an upper element and towards the junction zones 22in substantially equal streams. At each of these zones 22, the streams flowing along the corresponding pair of downwardly converging sections IT are merged and thoroughlyintermixed. The total liquid delivered to this zone 22 is then divided equally between the two lower oblique element sections l1 diverging downwardly from that zone.

The elements It as shown in Fig.3, may be welded together as indicated at 23 at'their junctions 22 desirably in such a way that the weld does not extend between the lower element sections I! at these junctions. A weld irregularity on the bottom of a junction 22 between adjoining lower element sections I1 is apt to cause the liquid to drop therefrom vertically in the form of droplets. This dripping action would adversely affect the regularity ofliquid flow through the packing. By welding superposed elements It together at their abutting junctions 22, the formation of welds at the bottom of the junctionsbetween the angular sections [1 or the lower elements is avoided.

The elements iii are horizontally stacked one on top of the other in 'a vertical plane with contiguous elements in reverse or inverted contacting relationship as indicated, to form a vertical latticed layer 24 as shown in Figs. 4 and 5. The .meshes 2| of each layer 24 extend. in verticalrows with the junctions 22 of each row definingthe vertices of these meshes, and extending in vertical alignment, and the meshes of adjoining vertical rows medially staggered. This construction lends symmetry to the arrangement, provides a continuous solid path over which the liquid delivered to the top of the packing can flowdownwardly, aifords effective means of contacting the The vertical layers 24 are substantially identical as far as the size and shape of the'meshes 2i and of the diameter of the elements iii are concerned, and are arranged in face to face contact one behind the other to form the composite packing I I. The vertical layers 24 preferably are relatively displaced vertically-so that meshes 2! or "one layer are outofwave phase or registry ,6 with the "meshes of adjoininglayers. In the'specifi'c form shown in Figs. 4 and 5, the meshes 2! of alternate vertical layers 24 are in horizontal registry, while the meshes of intervening layers are in horizontal registry but medially staggered with respect to'the meshes of the-'othe'r'layers. In this honeycomb arrangement, the junction zones 220i one vertical layer 24 would be'disposed centrally with respect to the meshes '21 of adjoining layers. Each mesh 2| of a vertical layer 24 will thereby be divided by the adjoining layer into four openings 25 which 'are similar and-of equal area and shape, and the horizontally opposed elements [6 of adjoining layers "will intersect at the midway points '26 of the oblique element sections ll to form additionalliquid mixing zones at those points. Adjoiningelementsections I 1 will extend at equal inclination towards and from these intersections 26.

With the arrangement --as described, a small portion of a stream flowing from an abutment zone 22 along an elementsection l'lof a vertical layer 24, merges at an intersection zone 26 with 'a similar portion of the stream flowing from'another abutment'zone 22 along an element section of an adjoining vertical layer 24. 'In this manof an inch apart.

ner, the liquid in one vertical layer 24 is not only distributed and mixed substantially uniformly throughout the width of that layer, but is also distributed and mixed with the liquid of adjoining vertical layers. Substantially uniform distribution and mixing of the liquid throughout the entire horizontal flow section of the packing II is thereby assured. The interstices or openings 25 defined by the adjoining layers 24 are large enough to prevent capillary filming of the downward flowing liquid across these openings, but are as small as possible having regard for theliquid-gas load. Also, the diameter of the elements [6 is desirably large enough so that the spaces between horizontally aligned elements of alternate layers are not spanned by the capillary filming of the liquid. To achieve this result,the diameter of the elements IS varies according to the character of the liquid being treated. In a specific application, the elements It are about one-tenth of an inch in diameten'and consequently the alternate layers are spaced one-tenth In any caseythese spaces or openings between alternate elements should be such that they do not se'al'with the liquidunder treatment.

The packing of Figs'3'to 5 may be constructed in horizontal strips onsheetsifil, and thesesheets may then be stacked in tiers :foriassembly :as

shown in Fig. 4. Each of these sheets 2? may consist'of a horizontal row of contiguous zig zag elements it with alternate elements lfilreversely bent with respect to the intervening elements, and these elements interconnected together, as for example, by welds 23' at the intersections to form aunit. These welds 23 preferably are'on the uppersides of the intersections to prevent irregularities-atthe bottom of each intersection 26 which would be undesirable, Since'they might cause the liquid to flow therefrom in the form" of droplets or to be distributed unequally. The sheets 2? are stackedwith the apices l8 and $9 of the elements idol superpose'dsheets in abutment. These sheets 2? can be held-against horizontal displacement by welds '23 at the abutting 'apices l8 and I9 together, or if desired, other holding means may be employedas will'bem'a'de more apparent.

If "desired, the composite *pa'cking may bema'de up of separate vertical layers 24 relatively displaceable vertically, or separate horizontal sheets 27 relatively displaceable horizontally. Either one of these arrangements may be employed, where, for example, it is desired to vibrate some of the vertical layers 2t or some of the horizontal sheets 27 through small amplitudes to promote turbulences in the fluid flow or to prevent clogging of the packing when used with liquid carrying solids in suspension.

Each zig-zag element is at its peak apices It supports the elements above it in the same vertical layer 24. The weighting of these elements It at their apices It tends to flatten or expand the elements [5 and thereby spread them endwise. The layers 2d are desirably arranged to extend parallel to the partition plates 53, so that the sides of these layers extend along the wall of the tower If). Since the ends of the expansibly stressed elements It are confined by the walls of the tower I9 containing the packing, each of these elements will act as an individual truss of considerable strength. The tendency of the elements It to flatten out under weighting pressure is advantageously employed to assure the complete filling of the tower is in which they are confined. Under this pressure, the circular sides of the packing l i yieldably press against the filling material I l in the spaces between the packing sides and the wall of the tower, so that these spaces are effectively sealed against flow of fluid. This is particularly important, since the countercurrent fluids tend to segregate or collect on the enclosing walls, thus upsetting their uniform distribution.

The packing layers 24 are set snugly between the partition plates it, so that the outside layers fit tightly against these partition plates and effectively serve to dam the liquid flowing down along these plates. The liquid thereby is returned by this damming action to mixing points in the packing from which it will be uniformly redistributed partly to the side walls of the tower it! and partly to the packing itself.

Although the operation of the packing of Figs. 1 to 5 will be apparent from the foregoing description, it is briefly summarized at this point. In the use of this packing, the liquid with which it is desired to contact the ascending gases is delivered to the top section of the packing as described, and divides itself into a number of predetermined exposed filmiform streams which flow obliquely downwardly along the elements it on regular zig-zag courses in a direction generally counter to the direction of the flow of th gas. The maximum of liquid surface is thereby exposed to the action of the ascending gas. The liquid stream flowing down along a single oblique section ll of an element It in one vertical layer 24, merges at an abutment junction 22 with the liquid stream flowing down an adjoining oblique section of the element. At this junction 22, the two streams are thoroughly intermixed, and the resulting mixture is then subdivided and redistributed equally between the element sections ll diverging downwardly from the junction. Each of these diverging element sections ll constitutes part of another pair of elements converging towards a junction 22, so that the two diverging distributed streams merge and intermix with other adjoining streams, and then again become subdivided. This process is repeated so that uniform mixing and distribution of the liquid throughout the width of each vertical layer 24 is assured. Also, a small portion of each liquid stream flowing along an oblique element section ll merges at an intersection zone 26 with a similar portion of the stream flowing along an oblique element section I! of the contiguous element of an adjoining vertical layer 24, and the mixed liquid is then equally subdivided between those parts of the element sections diverging downwardly from the intersection zone. The liquid in one vertical layer 24 is thereby not only distributed and mixed substantially uniformly throughout the width of the layer, but is also distributed and intermixed uniformly with the liquid of adjoining vertical layers.

If the flow along the different oblique element sections I? is not equal, the degree of irregularity will tend to become progressively reduced due to the fact that each section will divide the whole of the liquid reaching a given mixing zone 22 or 26 equally with its element partner in that zone. This is particularly important in the upper section of the packing, where the liquid feed may not be deposited uniformly over the top of the packing. By the equalizing process described, the distribution of the liquid under these conditions will become uniform in the upper section of the packing. Uniform distribution of the liquid when once attained near the top of the packing will persist to the bottom of the packing. The gas passing upward generally countercurrent to the liquid is subjected to sufficient turbulence to insure thorough mixing, thus avoiding the loss of efficiency which results when gas at the liquid-gas interface is not mixed as rapidly as possible with the main bulk of the gas, and when other purely local conditions within the packing tend to vary the composition of the gas across any section of the tower l0.

As a result of the packing construction of the invention, the velocity of the gas upwardly will be substantiall the same at any point in any plane at right angles to the general direction of flow. The maximum intimacy of contact and the maximum interaction between liquid and gas is obtained, and equilibrium is rapidly established between the material in either vapor or liquid phase immediatelly adjacent to the interface and the main bulk of the material comprising the phase. On any cross-section of the packing at right angles to the general direction of flow of the liquid and the gas, the composition of the gas is substantially the same and the composition of the liquid in its constituent streams is substantially the same. The pressure drop of the liquid passing through the packing and the amount of liquid retained by the packing under normal operating conditions is comparatively low. A comparatively long path of travel of the liquid passing through the packing is provided so that retention of the liquid for a period long enough to assure the necessary saturation or interaction with the gas is assured.

Figs. 6 and '7 show a packing in which the elements iii are all identical and are constructed, shaped and arranged in a manner similar to that indicated in connection with the construction of Figs. 3 to 5, but are held together in a different manner. In this form, there is provided a series of cross-rods 30 extending horizontally across the packing at right angles to the planes of the elements l6, and arranged in pairs with the two rods of each pair disposed in vertical alignment on opposite sides of each intersection zone 26. These rods 30 preferably are secured so that one of each pair is aflixed to one of the elements IE5 at the intersection it, while the other rod is secured to ageapra the, other. element t,the.intersection. In Fig.6, the arrows are applied to. some of the rods 3B'to, indicate the element it to which each is attached Bhese rods 3!! extending at right angles to the elements It fix the position of these elements, and may be either sweated or otherwise affixed to the elements as indicated, or may be woven with the elements to afiord a final pattern similar to that employed in the manufacture of wire gauze. The cross-rods 3B afiixed and mounted as described, prevent the intersecting elements [6 of adjoining vertical layers 24 from being relatively displaced generally lengthwise of the elements.

The elements lfi' diverge obliquely at such an angle from anintersection 2 that the liquid at the intersection tends to drain to them instead of forming liquid droplets. Also, by making the Kids. 3.11 of sufilciently small cross-section, the meniscus of the liqrid formed at the bottom of an intersection 26 will not extend below the rod 30 at that intersection, thereby reducing the tendency to dripping at the intersection.

To prevent relative displacement between the stjackedhorizontal sheets or strips 21, cross-rods 31; are provided, these extending parallel to the cross-rods 3G and being arranged in pairs with therods of each pair disposed in horizontal alignment on opposite sides of the abutment junctions 22' where the superposed packing sheets 2? meet. Arrows are applied to someof the cross-rods 3| to indicate the elements I6 to which each of the rods is attached. Some of the cross-rods 3| of one horizontal row are shown afiflxed to the peaks of alternate elements of'a' lower horizontal sheet 21, while the other cross-rods of the roware shown affixed to the bottom turns-of every other element It: staggered with respect to the alternate elements and disposed in the next upper horizontal sheet 21-. These cross-rods 3| may be sweated or otherwise afiixed to the elements in a manner similar to that indicated in connection with the cross-rods 35;

The method of assembly and attachment shown in- Figs. 6 and '7 may be employed, for example, where it is desired to install the packing in an existing tower to which interior access can beobtained only through manholes or other restricted openings. In installing a packing of the type shown in Figs. 6 and '7' in such a tower, thestraight rods or wires which comprise the elements it are made in the form of a strip having awidth which would allow its passage through the available tower opening. The straight ele ment rods or-wi-res which make up a horizontal packing sheet 2?, are arranged alongside of each other with the cross-rods 3t and Si properly attached thereto to fix the position of the elements l6 during fabrication and installation. These elements, rods or wires are then bent along pre--. determined lines to impart the required zig-zag pattern to the element, rods or wires. The mesh strip'so formed is then trimmed toconform to the circular shape of the tower walls, and the strips stacked and enmeshed to form the compositev packing shown in. Figs. 6 and 7. Since the distancehetween the partition plates 93 is an exact multiple of'the diameter of he rods or Wires constituting the elements it, the composite packing willfit snugly between the'plates.

Figs. 8 and Qshow a form of packing. which is similar to that indicated in Figs. 6' and. 7, except that; the superposed horizontal sheets 27; are; held against relative horizontal d' lacement by means of: angles. 3:3' extending transversely of; the elements: iii; At least two of. such. angleS .34.: would be required betweeneach-pair of contiguous horizontalsheetsZl. One of these angles 34 would-be snugly disposed in the horizontally aligned side corners formed between superposed alternate elements I6, while the other angle 31% desirably wouldbe reversely disposed in mirror image relationship withrespect to the first-mentioned-angle, and would-be snuglydisposed in the horizontally aligned side corners formed between superposed elements I6 staggeredwith respect to'the alternate elements. These angles 3d areeffixed desirably by welding to the elements 16 they contact, so that the horizontal packing sheets 21 are held against relative horizontal displacement lengthwise generally of the elements.

In Fig. 10 is shown another form of packing inwhich the zig-zag elements I611 extend generally vertically instead of horizontally. In all other respects, the packing is similar to that indicated in connection with the constructions of Figs. 6 and 7. As in the constructions of Figs. 6

and 7; the packing of Fig. 10 may be made of sheets 21 of standard width, which are meshed.- together vertically instead of horizontally. The

fitting of the packing sheets 21a to the curved I.

surface of the tower can be achieved by variations in the width of these packing sheets. The cross-rods 30a extending horizontally across the peeking at right angles to the planes of the elements Ilia are arranged in pairs with the two rods of each pair disposed in horizontal alignment on opposite sides of" each intersection zone 26a. These cross-rods 30a are desirablysecuredso that one of each pair is affixed to one of the elements Ita at the intersection 26a, while the other rod is secured to the other element of the intersection as indicated by the arrows applied to some of the cross-rods. The cross-rods am provided to prevent relative vertical displacement between the vertical packing sheets 2Ta are ar-. ranged in pairs with the rods of each pair disposed in vertical alignment on opposite sides of. the row of horizontally aligned abutment junctions 22a where the adjoining vertical packing sheets 21a meet. The arrows applied to some of the rods 3hr indicate the elements l6'a to which each of the rods is aflixed'.

In the construction of Fig. 10', each element l6a. supports its own we ght, and is yieldably pressed against adjacent elements. The effect of this weighting 'in expanding the packing against the curved wall of the tower I0 is similar to that obtained in the horizontal packing described in connection with the construction of Figs. 3; 4 and 5. The arrangement shown in Fig. 10 can be installed between the partition plates I3 and the packing held under tension untilthe last vertical layer has been installed. The release of this pressure causes each element It to expand under its own weight, and thereby serves: to eiiectively close the small gap which it isv necessary to leave in order to install the last verticali layer of the packing.

Fig. 11 shows a packing construction similar to that. shown in Fig. 10', except that the verti--. cal sheets 21a are held against relative vertical displacement. by means of angles 34w disposed snugly inthe corners formed at the abutment junctions 22a between adjoining sheets; One ofthese angles 34a is affixed by welding or the like to. the elements It of alternate vertical lay ers, while the other angle is aflixed to. the ele-.

ments. of intervening layers, as in the construc-.

tion of Figs. 8- and, 9.

- 11 the elements in each vertical layer are disposed in abutment in the same vertical plane. In the form of the invention shown in Figs. 12, 13, 14 and 15, the individual elements Nib are bent to form a zig-zag of equal successive turns as in the constructions of Figs. 3 to 11, but the contiguous horizontal elements instead of being reversely disposed in abutment in the same vertical plane, are disposed with the apices of adjoining elements in contacting overlapping relationshi to form liquid mixing zones 22b, and to define the meshes 21b between the elements. Contiguous elements |6b are interconnected at these junctlon zones 2% desirably by sweating, welding or the like.

In the arrangement of Figs. 12-15, the peak apices I So of a lower element 16b overlap the trough apices |8b respectively of an upper element in such a way that the outer point of the apex section of one element is in horizontal alignment with the inner corner point of the corresponding apex sect on of the other e ement. It is desirable not to have the outer point of the apex trough section of the u per element I61) extend below the inner corner point of the correspon ing apex peak section of the. lower element in order to avo d drinning at the junction zones 22?; as much as pos ible. In anv case, in order to avoid drip ing. the relative pos tion between t e two conti uous up er and lower elements l6b should be such that when licuid is flowing over them, the lowest trough a ex point of the upper element will not be below the meniscus of the liouid formed on the inner corner of the peak apex of the lower element. This re ative positioning of the two elements I61) var es accor ing to the apex an le of the lower element and the ph sical characteristics of the liouid. Adioining oblicue sections l 1b of an upper element l6b converge down ardly towards their junct on zone no at eoual inclinations, and corresponding adioining obli ue sections [1b of a lower element diverge downwardly from the junction zone at equal inclinations, which is the same as that of the upper element sections. The meshes 2lb formed between vert cally adjoining contiguous elements des rably are in the form of eouilateral parallelograms, and are specificallv shown substantiall snuare shape, althou h angles other than right angles may be em loyed.

The elements l6b are arranged in vertical sheets 40. each of which compri es a series of horizontal elements lGb positioned in apically overlapping relationship with alternate elements in the same plane as shown in Figs. 13 and 15. The vertical sheets 40 are desirably arranged in face to face contact with the meshes Zlb of adjoining sheets in horizontal registry and the junction zones 2% of adjoining sheets in contact and in horizontal alignment. In this ar-' rangement, since the meshes Zlb are not subdivided into smaller openings by the staggering of the alternate vertical sheets as in the constructions of Figs. 4 to 11, the width of the meshes 2lb would be much smaller than the corresponding meshes 2| in the construction of Figs. 4 to 11. Although all of the vertical sheets 49 are shown in horizontal mesh registry, as far as certain aspects of the invention are concerned, these sheets may be arranged in staggered relationship as in the construction of Figs, 4 to 11. The packing may be formed in vertical sheets 40 asdescribed, with the elements welded or otherwise interconnected to form a unit. a d

12 the difierent sheets may then be arranged one behind the other in the tower l0 between the partition plates l3.

Another method of assembly is to form hori- Zontal sheets ll, each comprising a horizontally aligned row of upper parallel elements 56b, and an adjoining horizontally aligned row of lower parallel elements 5b, the elements of the two rows overlapping at their apices and interconnected by welding or the like into a sheet unit. The horizontal sheets 4| so formed can then be stacked and intermeshed as shown in Figs. 14 and 15, and the sheets held together against vertical displacement by welding or the like.

In Figs 16 and 17 is shown a form of packing, in which each horizontal element [to is bent by equal alternate turns to form a regular zig-zag as in the constructions of Figs 3-15, but in which the opposed apices 18c and 190 of vertically adjoining elements overlap into interlocking engagement with horizontal rods 25 extending sub stantially at right angles to the planes of the elements. The apical overlap between contiguous elements Ithis such as to leave openings through which the rods 45 extend, so that the elements ltc of an upper horizontal row support the rods 45, while the elements of the. lower contiguous horizontal row hang down and are suspended from these rods. The apical junctions 220, where vertically adjoining elements overlap and interlock with the rods 45, form liquid mixing zones. Since the lower bends of upper elements 160 project below the inner corners of the upper bends of the lower elements at these mixing zones 22c, provisions must be made to prevent dripping of the liquid from these projections. For that purpose, the angle of the zig-zag bends of the elements Itb are more acute than those in the constructions of Figs. 3-15 described, and the rods 45 and elements Ito are dimensioned to insure that the bottom of the lower bends of the upper elements do not project below the bottom of the meniscus of the liquid formed in the inner corners of the upper bends of the lower elements. As a result of the acuteness of the apex angles of the elements lee, the meshes 2 [0 formed by these elements will be substantially diamond shaped with their longer axes extending vertically.

The packing can be built and assembled from the top down in successive horizontal layers, the last layer being suspended through the interlocking rods 45 from the next upper layer. All the vertical sheets of the packing may be disposed in face to face contact and in horizontal registry, or the sheets may be alternately staggered in a manner similar to that already described in connection with the construction of Figs. 3 to 15 to divide the meshes 2|c into smaller equal openings.

In the constructions of Figs. 4 to 16, vertical sheets have been arranged with alternate sheets aeao oze 13 increased spacing of: the elements may be desirable in some cases.

Figs, 18- and 19 show a construction. in which the distance between successive horizontally aligned parallel zig-zagged" elements I 611 is a. multiple of the diameter of the elements, and the intervening elements are equally and symmetrically displaced out of wave phase relationship with each other and with the aligned elements; The elements l ed made of rod-like or other similar stock, are identical in crosssectional size and shape, and are zig-zagged to form equal successive oblique turn sections lld having equal inclinations. The distance between. horizontally aligned parallel elements ltd is shown as three times the diameter of the elements, interposed between-these two horizontally aligned elements Hid are three similar elements ltd disposed in face to face contact with their peak apices 19d disposed at the same horizontal level, and displaced, by equal distances out of wave phase or horizontal registry. Where the successive elements lEid' intersect, they form liquid mixing zones 2601. The elements ltd may be connected together at these intersection mixing zones d by Welding or the like as previously described, to form horizontal sheets 2111 as shown. in Figs.. 18 and 19. These sheets 21d may be stacked with: the trough apices id of the elements 16d of an upper sheet in abutting coplanar contacting relationship with the peak apices I90! of the corresponding elements of a lower sheet, as in the construction of Figs. 3, 4 and 5, and as shownin Figs. 18 and 19, to form liquidimixing zones 22d where the elements. abut, or may be stacked withv the trough apices 19d of the elements lfidof the upper sheet in overlapping contacting relationship with the peak apices ledlof the corresponding elements of the lower sheets, as shown in the constructions of Figs. 12 to 15, to-form liquid mixing zones where these elements are in overlapping contact. The elements ltd of superposed sheetsv 21d. may be welded as previously described, or otherwise interconnected where they contact at their apices. Also, if desired, the horizontal sheets Zld may be. enmeshed and interconnected by means of cross-rods as-in. the construction OfFigs; 17 and 18.

In all the forms shown, the-liquid with which itis desired to contact the gasestflows regularly and substantially evenly in a series ofv thin films over the surfaces-10f, the; oblique sections of the packing elements-in a direction generally'counter to the direction. of the. flow of they vapor. The liquid flowing down a; singleoblique element section of the packing. is regularly mixed. with liquid flowing down adjacent oblique element,

sections of the packing, and the resulting mixture is. then redistributed among oblique element sections diverging. from the zone of mixing, Each. of these latter elementsections carries substantially the same aliquot part of the liquid reacliing the mixing zone from above. The spaces or openings between the elements are such as to prevent the formation of capillary filming of cerned; any number of oblique element sections at equal inclinations may converge downwardly towards to a juncture to form a liquid mixing zone, and a similar number of. oblique element sections at equal inclinations may diverge downwardly from each juncture zone, as shown in my copending application Serial No. 529,246, filed April 3, 1944' (now Patent No. 2,405,594, dated April 13, 1946). This copending application shows an arrangement in which a triad of converging and diverging elements at equal inclinations is provided at each junction mixing zone. As alternative forms, tetrads and pentads of elements are shown provided at each junction zone.

Also, as far as the broader aspects of the invention areconcerned, instead of having all of the zig-zag elements in parallel vertical planes, these zig-zag elements may be crisis-crossed at right angles to each other, as shown in my copending application Serial No. 528,541, filedlvlarch 29, 1944 (now Patent No. 2,424,248, dated July 22, 1947 so that the peaks of one element are loopedover and supported on the troughs of the other.

It also will be understood that as far as the broader aspects of the invention are concerned,

instead of having the elements in the form of separate slender units zig-zagged as shown, the elements ma be part of an expanded vertical lath sheet, as shown in my copending application Serial No., 528,542, filed March 29, 1944, abandoned'as of Nov. 15, 1947.

Also, as far as the broader-aspects of the invention are concerned, instead of having elements zig-zagged and arranged as described, the elements may be straight and criss-crossed. obliquely at equal inclinations to form a lattice with a series, of intersectional liquid mixing zones as shown. in my copending application Serial No. 521,049, filed February 4, 1944 (now Patent No. 2,405,593 dated April 13, 1946).

The type of packing herein described is applicable for contacting liquid and gas devices, such as. bubble towers, scrubbers, cooling towers, fractionating towers and the like, but it is not intendedithat the packing should be limited to these types of equipment. It is also contemplated that the packing itself may be used as a catalyst. Under these conditions, the packing itself may, for example, be made of nickel, copper, or any or the solid materials having the required catalytic properties. For that purpose, the catalytic packing may serve to increase the rate of reaction by contact with a gas, or by contact with a liquid. As another example of the use of the packing of the invention, it may serve as a catalyst carrier, the

catalyst, 101' example, being formed into beads which are threaded on the elements defining the packing. Also, if desired, the surface of the packing. elements may be subjected to special treatment to form a layer of catalytic material thereon. As another example of the use to which the packing may be put, it may serve as a carrier of a catalyst which takes the form of a liquid, and particularl a high viscous liquid such as phosphoric acid.

Inasmuch as parts of the elements extended in a downwardly inclined direction from the inner wall of the tower iii, liquid which reaches the wall byway of some of the elements will flow away from the wall by way of other elements and thus will tend to retain the liquid in the packing and prevent short circuiting flow down the wall of the tower.

The velocity of the vapor flowing upwardly through the packing will cause or tendto cause,v

the liquid on the vertically inclined portions of the elements to assume a streamlined or tear drop shape such as would present the minimum resistance to the flow of vapors and this, together with the surface efiects which become pronounced with thin films of liquid, will have the effect of distributing the liquid over the surfaces of the elements with a tendency for a major part of the liquid to flow down the upper parts of the ele ments, the amount of liquid so flowing increasing with increased vapor velocity. The effect of this is to insure the maximum exposure of the liquid to the vapor and to facilitate the mixing of the streams of liquid at the juncture points.

As many changes can be made in the apparatus disclosed. herein, and many apparently Widely different embodiments of the invention can be made without departing from the scope of the claims, it is intended that all matter contained in the above description or shown in the accompanydrawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

l. A packing for a liquid contacting device comprising a plurality of zig-zag slender elements of equal turns, the apex sections of adjoining elements being in contact to form between said adjoining elements a row of equal meshes, and to form liquid mixing junction zones where these apex sections are in contact, and a plurality of cross-rods arranged in pairs with the rods of each pair extending on opposite sides of a junction zone to prevent the elements at said latter zone from being relatively displaced.

2. A packing for a liquid contacting device comprising a plurality of parallel vertical layers, each including a series of zig-zag slender elements of equal turns, the apex sections of adjoining elements in each layer being in contact to form between said elements a row of equal meshes, and to form liquid mixing junction zones where these apex sections are in contact, and a series of horizontal cross-rods extending parallel substantially at right angles to the vertical planes of said layers and arranged in pairs, the rods of each pair extending on opposite sides of a junction zone and connected to respective elements at said zone to prevent the elements at said zone from being relatively displaced.

3. A packing for a liquid contacting device, comprising a plurality of parallel vertical layers, each including a plurality of zig-z-ag slender elements of equal turns, the apex sections of adjoining elements in each layer being in abutting relation and in the same vertical plane to form a row of equal meshes between said elements and to form liquid mixing junction zones where these apex sections are in contact, said layers being arranged so that rows of horizontally aligned junction zones are formed, and a series of horizontal cross-rods extending parallel substantially at right angles to the vertical planes of said layers and arranged in pairs, the rods of each pair extending on opposite sides of a row of horizontally aligned junction zones and being connected to respective elements at said latter zones to prevent the elements at said latter zones from being relatively displaced.

4. Vapor and liquid contacting apparatus packing having a plurality of sheets, each sheet extending in a generally vertical plane, said sheets comprising a plurality of slender elements with a continuous surface, the elements being of zig-zag shape with alternately arranged apices interconnected by oblique sections, the elements of each sheet being adjacently disposed in inverted relationship with the trough apices of one element secured in registering abutment with the peak apices of one of the adjacent elements in said sheet and the peak apices of said one element being secured in registering abutment with the trough apices of the other of the adjacent elements in said sheet, the abutting apices thereby forming liquid mixing zones the sheets of said packing being disposed in face to face relationship in contiguous parallel generall vertical planes.

5. Vapor and liquid contacting apparatus packing for a contacting device with generally vertical countercurrent flow, said packing having a plurality of sheets, each sheet extending in a generally vertical plane, said sheet comprising a plurality of slender elements with a continuous surface, the elements being of zig-zag shape with alternately arranged apices interconnected by oblique sections, the elements of each sheet being adjacently disposed in inverted relationship with the trough apices of one element secured in registering abutment with the peak apices of one of the adjacent elements in said sheet and the peak apices of said one element being secured in registering abutment with the trough apices of the other of the adjacent elements in said sheet, the abutting apices thereby forming liquid mixing zones, the sheets of said packing being disposed in face to face relationship in contiguous parallel generally vertical planes, with the zones of alternate sheets being staggered with respect to zones of sheets adjacent said alternate sheets.

6. Vapor and liquid contacting apparatus packing having a plurality of sheets, each sheet extending in a generally vertical plane, said sheets comprising a plurality of slender elements with a continuous surface, the elements being of zigzag shape with alternately arranged apices interconnected by oblique sections of equal length extending from said apices at equal angles, the elements of each sheet being adjacently disposed in inverted relationship with the trough apices of one element secured in registering abutment with the peak apices of one of the adjacent elements in said sheet and the peak apices of said one element being secured in registering abutment with the trough apices of the other of the adjacent elements in said sheet, the abutting apices thereby forming liquid mixing zones, the sheets of said packing being disposed in face to face relationship in contiguous parallel generally vertical planes.

7. Vapor and liquid contacting apparatus packing having a plurality of sheets, each sheet extendin in a generally vertical plane, said sheets comprising a plurality of slender elements with a continuous surface, the elements being of zigzag shape with alternately arranged apices interconnected by oblique sections, the elements of each sheet being adjacently disposed in inverted relationship with the trough apices of one element secured in registering abutment with the peak apices of one of the adjacent elements in said sheet and the peak apices of said one element being secured in registering abutment with 17" the zones of alternate sheets being staggered with respect to zones orsheetsadi ce t alternate sheets.

8.-Vapor and liquid contacting apparatus packing having a plurality of sheets, each sheet extending in a generally vertical plane, said sheets comprising a plurality of generally hori;

zontally extending slender elements with a continuous surface, the elements being of zig-zag shape withalternately arranged apices interconnected by oblique sections, the elements of each sheet being adjacently disposed in inverted relationship in the same vertical plane and with the trough apices of one element secured in registering abutment with the peak apices of one of the adjacent elements in said sheet and the peak apices of said one element being secured in registering abutment with the trough apices of the other of the adjacent elements in said sheet, the abutting apices thereby forming liquid mixing zones, the sheets of said packing being disposed in face to face relationship in contiguous parallel generally vertical planes.

9. Vapor and liquid contacting apparatus packing having a plurality of sheets, each sheet extending in a generally vertical plane, said sheets comprising a plurality of slender elements With a continuous surface, the elements being of zig-zag shape with alternately arranged apices interconnected by oblique sections, the elements of each sheet being adjacently disposed in inverted relationship With the trough apices of one element secured in registering abutment with the peak apices of one of the adjacent elements in said sheet and the peak apices of said one element being secured in registering abutment with the trough apices of the other of the adjacent elements in said sheet, the apices of said one element and said adjacent elements being brought together in overlapping contact relationship, the abutting apices thereby forming liquid mixing zones, the sheets of said packing being disposed in face to face relationship in contiguous parallel vertical planes.

l0. Vapor and liquid contacting apparatus packing having a plurality of sheets, each sheet extending in a generally vertical plane, said sheets comprising a plurality of slender elements with a continuous surface, the elements being of zig-zag shape with alternately arranged apices interconnected by oblique sections, the elements of each sheet being adjacently disposed in inverted relationship with the trough apices of one element secured in registering abutment with the peak apices of one of the adjacent elements in said sheet and the peak apices of said one element being secured in registering abutment with the trough apices of the other of the adjacent elements in said sheet, the apices of said one element and said adjacent elements being brought together in overlapping contact relationship, the abutting apices thereby forming liquid mixing zones, the sheets of said packing being disposed in face to face relationship in contiguous parallel vertical planes, with the zones of alternate sheets in horizontal register with respect to the mixing zones of adjacent sheets.

ll. Vapor and liquid contacting apparatus packing having a plurality of sheets, each sheet extending in a generally vertical plane, said sheets comprising a plurality of slender elements ith a continuous surface, the elements being of zig-zag shape with alternately arranged apices interconnected by oblique sections, the elements of each sheet being adjacently disposed in in verted relationship and in the same vertical plane with the trough apices of one element in registering abutment with and secured to the apices of one of the adjacent elements in said sheet and the peak apices of said one element being in registering abutment with and secured to the trough apices of the other of the adjacent elements in said sheet, the abutting apices thereby forming liquid mixing zones, the sheets of said packing being disposed in face 'to face relationship in contiguous parallel generally vertical planes.

l2. Vapor and liquid contacting apparatus packing having a plurality of sheets, each sheet extending in a generally vertical plane, said sheets comprising a plurality of slender elements with a continuous surface, the elements being of zig-zag shape with alternately arranged apices interconnected by oblique sections, the elements of each sheet being adjacently disposed in inverted relationship and in the same vertical plane with the trough apices of one element in registering abutment with and secured to the peak apices of one of the adjacent elements in said sheet and the peak apices of said one element being in registering abutment with and secured to the trough apices of the other of the adjacent elements in said sheet, the abutting apices thereby forming liquid mixing zones, the sheets of said packing being disposed in face to face relationship in contiguous parallel generally vertical planes, with the zones of alternate sheets being staggered with respect to zones of sheets adjacent said alternate sheets.

13. Vapor and liquid contacting apparatus packing having a plurality of sheets, each sheet extending in a generally vertical plane, said sheets comprising a plurality of slender elements with a continuous surface, the elements being or zig-zag shape with alternately arranged apices interconnected by oblique sections, the elements of each sheet being adjacently disposed in inverted relationship with the trough apices of one element disposed in registering abutment with the peak apices of one of the adjacent elements in said sheet and the peak apices of said one element being disposed in registering abutment with the trough apices of the other of the adjacent elements in said sheet, the abutting apices thereby forming liquid mixing zones, the sheets of said packing being disposed in face to face relationship in contiguous parallel generally vertical planes, and a plurality of cross-rods arranged in pairs with the rods of each pair extending and secured in position on opposite sides of the junction formed at said mixing zones to prevent the elements at said latter zones from being relatively displaced.

l4. Vapor and liquid contacting apparatus packing having a plurality of sheets, each sheet extending in a generally vertical plane, said sheets comprising a plurality of slender elements with a continuous surface, the elements being of zig-zag shape with alternately arranged apices interconnected by oblique sections of equal length extending from said apices at ecual angles, the elements of each sheet being adjacently disposed in inverted relationship with the trough apices of one element secured in registering abutment with the peak apices of one of the adjacent elements in said sheet and the peak apices of said one element being secured in registering abutment with the trough apices of the other of the adjacent elements in said sheet, the apices of said one element and said adjacent elements being acne-m9:

brought together in overlapping contact relationship, the abutting apices thereby forming liquid mixing zones, the sheets of said packing being disposed in face to face' relationship inconti-guous parallel generally vertical planes.

FRANCIS L. MELVILL.

REFERENCES CITED:

The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Wood June 11, 1889 Number Number Number 

